Method for diagnosing mechanical anomalies and electromagnetic interferences in a gas flowmeter

Abstract

The application discloses a kind of gas flowmeter diagnosis mechanical exception and electromagnetic interference method, it is related to gas flowmeter technical field, to solve the technical problem that turbine flowmeter can only be known when appearing card table or flow deviation is huge that flowmeter appears fault. Including S1, start monitoring and capture flowmeter pulse signal, pre-processing eliminates invalid data, extract effective high / low level length and single circle time consumption, S2, match preset regular flow range, determine regular working condition enters S4, irregular working condition enters S3, S3, compare adjacent level length, according to preset threshold value determine sudden acceleration or emergency stop event and trigger alarm, S4, analyze continuous multiple circle time consumption deviation rate, up to standard then determine uniform speed enters S5, not up to standard return S1.The application captures the real problem that is missed in prior art due to unobvious fault signal, significantly improves the accuracy and reliability of fault judgment, solves the problem that prior art relies on manpower and has high misjudgment rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas flow meters, in particular to a method for diagnosing mechanical abnormalities and electromagnetic interference of a gas flow meter. BACKGROUND

[0002] In the fields of industrial production, city gas supply, energy metering, etc., gas flow meters are the core equipment for realizing accurate measurement of gas flow. Among them, the waist wheel flow meter and the turbine flow meter are widely used in the flow monitoring scenes of various gases such as natural gas, liquefied gas, and industrial tail gas, due to their advantages of high metering accuracy, strong stability, wide adaptability to flow range, etc.

[0003] The core working principle of such flow meters is based on the signal sensing mechanism of magnetic steel-sensor. On the rotor, i.e. the waist wheel or turbine component, of the flow meter, evenly distributed magnetic steels are embedded. When the rotor / turbine rotates with the gas flow, the magnetic steels will periodically pass through the signal sensor. The sensor outputs a pulse signal with high and low levels alternately by sensing the magnetic field change of the magnetic steels. Finally, the gas flow is converted from the frequency and period of the pulse signal, and the metering process is completed.

[0004] The prior art diagnoses faults of the flow meter through regular intensive inspection and manual inspection. However, early-stage slight wear, tiny foreign matter or weak electromagnetic interference only show weak fluctuations in the pulse signal, and the flow deviation is within the allowable range. The prior art cannot capture it. The middle-stage fault aggravates to cause the flow deviation to expand by more than 10% of the normal range, but it has not reached the huge standard, and it is still difficult to detect. Until the late-stage, the turbine is stuck, the metering is stopped, or the flow deviation exceeds 20% to cause settlement disputes, the fault can be inferred through manual or data anomaly, and the early repair opportunity is completely missed. In view of this, we propose a method for diagnosing mechanical abnormalities and electromagnetic interference of a gas flow meter. SUMMARY

[0005] The purpose of the present application is to overcome the shortcomings of the prior art, adapt to the needs of reality, and provide a method for diagnosing mechanical abnormalities and electromagnetic interference of a gas flow meter, to solve the technical problem that the current turbine flow meter can only know that the flow meter has failed when the meter is stuck or the flow deviation is huge.

[0006] To solve the above technical problems, the present application provides the following technical scheme: a method for diagnosing mechanical abnormalities and electromagnetic interference of a gas flow meter, comprising the following steps:

[0007] S1, start listening and capturing the pulse signal of the flow meter, pre-process to eliminate invalid data, and extract the valid high / low level time and single-turn time consumption;

[0008] S2, match the preset normal flow range, determine the normal working condition to enter S4, and the abnormal working condition to enter S3;

[0009] S3, compare the adjacent level duration, determine sudden acceleration or sudden stop event according to the preset threshold and trigger the alarm;

[0010] S4, analyze the time deviation rate of continuous multiple turns, if it meets the standard, determine uniform speed and enter S5, if it does not meet the standard, return to S1;

[0011] S5, calculate the duty cycle deviation value, and according to the exceeding standard, distinguish mechanical wear / foreign matter jam or electromagnetic interference and trigger the alarm;

[0012] S6, continuously monitor the subsequent signal, and clear the alarm state when the alarm is not met and the deviation value is normal.

[0013] Preferably, the step S3 specifically comprises the following steps:

[0014] S301: from the preprocessed signal data, extract the time of any group of adjacent high and low levels, denoted as last level time and this level time ;

[0015] S302: sudden acceleration judgment: compare with the preset acceleration abnormal threshold , with the preset acceleration abnormal threshold ,

[0016] satisfy > and < , determine sudden acceleration, execute step S304, if not satisfied, execute step S303;

[0017] S303: sudden stop judgment: compare with the preset sudden stop abnormal threshold , with the preset sudden stop abnormal threshold ,

[0018] satisfy < and > , determine sudden stop, execute step S304;

[0019] S304: trigger mechanical damage alarm system to generate mechanical damage warning / alarm signal, output alarm information through display screen, remote communication module, at the same time, record , and current flow value at the time of alarm, facilitate subsequent fault tracing and troubleshooting;

[0020] If the above conditions are not met, return to step S1.

[0021] Preferably, in the step S4, the uniform speed determination formula is: If the uniform speed operation condition is determined, step S5 is entered, in which: is the maximum value in the circle time consumption, , is the sample size of the circle number, is the minimum value in the circle time consumption, is a preset uniform speed determination threshold; if the above conditions are not met, the non-uniform speed operation condition is determined, and the step S1 is returned.

[0022] Preferably, in the uniform speed determination formula, the preset uniform speed determination threshold : under the on-site conventional flow condition, not less than 100 groups of circle time consumption data are collected, the maximum value of all calculation results is taken as .

[0023] Preferably, the step S5 specifically includes the following steps,

[0024] S501: calculating the duty cycle deviation coefficient of each circle: if the flowmeter is embedded to the magnetic steel, one revolution will generate a level sequence, wherein, is the high level time of the group, is the low level time of the group, for the uniform speed operation condition determined in S4, the duty cycle deviation coefficient of each group of high and low levels in each circle is calculated according to the formula ;

[0025] S502: non-uniform mechanical wear / fixed foreign matter determination each of the values of each circle is checked: if any of the values meets is a preset fault distinguishing threshold, the non-uniform mechanical wear or the existence of fixed foreign matter is determined, S504 is executed, and all values meet step S503 is entered.

[0026] S503: electromagnetic interference determination each of the values of each circle is checked: if all the values meet , but there are ​​​If momentary fluctuations or unstable signal amplitude occur, and factors such as mechanical component jamming or wear are ruled out, it is determined to be electromagnetic interference. Step S505 is then executed. Continuous and stable Return to step S1;

[0027] S504: Triggers the mechanical wear alarm system to generate a mechanical wear / foreign object jamming alarm signal;

[0028] S505: Triggers the electromagnetic interference alarm system to generate an electromagnetic interference alarm signal.

[0029] Preferably, in step S502, Data Acquisition: Data were collected from normal flow meters and abnormal flow meters containing fixed foreign objects at the site under normal flow conditions. Data; Extracting normal flow meters The maximum value is used to confirm the interval where normal and abnormal data do not overlap, and to verify this. The effectiveness of differentiation, extraction of abnormal flow meters Minimum value; take the abnormal flow meter value. Minimum value as .

[0030] Preferably, step S6 specifically includes the following steps:

[0031] S601: Alarm reset condition judgment: If the data of 3 consecutive cycles meets the judgment in step S3, the alarm will not be triggered; if the judgment in step S5, there is no fault, proceed to step S602.

[0032] S602: Clear the mechanical alarm signal and return to step S1.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] 1. This invention utilizes standardized signal analysis and formulaic judgment logic. It uses the cycle time deviation rate formula to determine uniform speed conditions and the duty cycle deviation coefficient formula to distinguish between mechanical wear and electromagnetic interference. Both are based on objective signal parameters and preset field adaptation thresholds for automated judgment, eliminating the need for subjective human intervention. This avoids misjudging normal flow fluctuations as mechanical wear. Furthermore, through refined time-domain signal analysis, it can capture real problems that are missed in existing technologies due to unclear fault signals, significantly improving the accuracy and reliability of fault judgment. This solves the problem that turbine flow meters only show faults when they jam or have huge flow deviations.

[0035] 2、The application can also identify sudden acceleration and sudden stop caused by sudden change of gas pressure in real time by extracting adjacent high and low level time and combining the threshold value obtained by field sampling, and once such instantaneous impact is detected, the system will immediately trigger a mechanical damage alarm, timely warning the risk of mechanical damage of the flowmeter, quickly responding at the key node causing mechanical damage of the flowmeter, helping staff to intervene and process in time, effectively preventing serious mechanical damage such as rotor breakage and turbine deformation, prolonging the service life of the flowmeter, and reducing equipment maintenance cost and downtime loss. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 The method flowchart of the application. DETAILED DESCRIPTION

[0037] Embodiment: As shown in the figure, the method for diagnosing mechanical abnormalities and electromagnetic interference of a gas flowmeter according to the application comprises the following steps: Figure 1

[0038] S1: Signal acquisition and initial preparation: after starting the diagnosis system, the system enters a signal listening state, continuously waits for the high and low level pulse signal output by the magnet-sensor assembly of the flowmeter, and captures the effective pulse signal until the effective pulse signal is captured, and the captured pulse signal is preliminarily processed to eliminate invalid data such as abnormal peaks and discontinuous data caused by signal interference, and the high level time, low level time and total time consumed per rotation in the effective signal are extracted, and the obviously collected error data is eliminated to provide clean basic data for subsequent analysis.

[0039] S2: Normal flow judgment: match the preset normal flow range, determine the normal working condition to enter S4, and the abnormal working condition to enter S3.

[0040] S201: Normal flow threshold value matching:

[0041] The circle time consumed per rotation or the pulse frequency of the current collected flowmeter is matched with the range, such as [1.2s, 1.8s] or the pulse frequency range, such as [0.5Hz, 0.8Hz], corresponding to the preset normal flow through field sampling.

[0042] S202: Determine whether it is in normal flow:

[0043] If the current data falls within the normal flow range, it is determined to be a normal flow working condition, and step S4 is entered.

[0044] If the current data is outside the normal flow range, it is determined to be an abnormal flow working condition, and step S3 is entered.

[0045] ​​​​​S3: Rapid start and sudden stop judgment: compare the adjacent level time, determine sudden acceleration or sudden stop event according to the preset threshold and trigger alarm;

[0046] S301: Extract the time of any group of adjacent high and low levels from the preprocessed signal data, denoted as last level time and this level time .

[0047] S302: Sudden acceleration judgment: compare with the preset acceleration anomaly threshold , with the preset acceleration anomaly threshold .

[0048] If > and < , it is determined as sudden acceleration, step S304 is executed, otherwise step S303 is executed;

[0049] S303: Sudden stop judgment: compare with the preset sudden stop anomaly threshold , with the preset sudden stop anomaly threshold .

[0050] If < and > , it is determined as sudden stop, step S304 is executed;

[0051] If the above conditions are not met, it is determined that there is no rapid start / sudden stop anomaly, and step S1 is entered to continue waiting and collecting the next round of pulse signals

[0052] S304: Trigger mechanical damage alarm system to generate mechanical damage warning / alarm signal, output alarm information through display screen and remote communication module, and record the , and current flow value at the time of alarm for subsequent fault tracing and troubleshooting.

[0053] S4: Constant speed state judgment: analyze the time deviation rate of continuous multiple turns, and if it meets the standard, it is determined as constant speed and enters S5, otherwise it returns to S1.

[0054] S401: From the historical data preprocessed in step S1, select the time consumption data of the last turns, denoted as , wherein is the time consumption of the turn .

[0055] S402: Calculate the maximum and minimum of the circle time consumption

[0056] S403: Constant speed determination and branch According to the formula , calculate the ratio, and compare it with the preset constant speed determination threshold , the threshold : under normal flow conditions in the field, collect no less than 100 groups of circle time consumption data , calculate for each group of data , take the maximum value of all calculation results as ;

[0057] If it is determined to be a constant speed running condition, go to S5; if it does not meet the above conditions, it is determined to be a non-constant speed running condition, such as normal acceleration / deceleration, return to step S1. S5: Non-uniform wear and electromagnetic interference judgment: calculate the duty cycle deviation value, and according to the exceeding standard situation, distinguish mechanical wear / foreign matter jamming or electromagnetic interference and trigger alarm;

[0058] S501: Calculate the duty cycle deviation coefficient of each circle: if the flowmeter is embedded with

[0059] magnetic steel, a turn will produce a level sequence, where is the high level time of the first group , and is the low level time of the first group. For the constant speed condition determined by S4, calculate the duty cycle deviation coefficient of each high and low level in each circle according to the formula .

[0060] S502: Non-uniform mechanical wear / fixed foreign matter determination: check each of the values one by one: if any one satisfies , where is the preset fault differentiation threshold, which is obtained by: collecting the data of the normal flowmeter and the abnormal flowmeter containing fixed foreign matter under normal flow in the field respectively, extracting the maximum value of the normal flowmeter (used to confirm that the normal and abnormal data have no intersection interval, and verify the effectiveness of ) and the minimum value of the abnormal flowmeter, taking the minimum value of the abnormal flowmeter as the threshold value , and the minimum value of the abnormal flowmeter​​​​​​ Minimum value as This indicates that the external force has disrupted the level stability of the uniform rotation, and it is determined to be non-uniform mechanical wear or the presence of fixed foreign objects, so S504 is executed.

[0061] If all All meet Enter S503.

[0062] S503: Electromagnetic interference detection for each revolution indivual Check each value one by one: if all However, it exists If instantaneous fluctuations or unstable signal amplitude occur, and factors such as mechanical component jamming or wear are ruled out, it is determined to be electromagnetic interference. This indicates that the duty cycle of high and low levels under uniform speed conditions is abnormal due to external interference, and is determined to be electromagnetic interference. Step S505 is then executed.

[0063] Special Note: If the flow meter only has one pair of magnets embedded... Electromagnetic interference and non-uniform mechanical wear / fixed foreign objects The signal characteristics are consistent, but it is necessary to combine the on-site conditions, such as whether there is a strong magnetic source, to make an auxiliary judgment.

[0064] If all All meet If no mechanical wear or electromagnetic interference is detected, return to step S1.

[0065] S504: Triggers the mechanical wear alarm system to generate a mechanical wear / foreign object jamming alarm signal, outputs alarm information, and records the alarm time. Distribution data provides a basis for subsequent fault location, such as replacing worn parts and removing foreign objects.

[0066] S505: Triggers the magnetic interference alarm system to generate an electromagnetic interference alarm signal, outputs alarm information and prompts for investigation of nearby strong magnetic equipment, and records the time period of interference occurrence to assist in the on-site investigation of interference sources.

[0067] S6: Alarm Reset: After any alarm is triggered, the system will not interrupt signal acquisition and will continue to monitor subsequent pulse signals. , and adjacent level time , Data, including time per lap Duty cycle deviation coefficient and adjacent level time , data.

[0068] S601: Alarm reset condition judgment If the subsequent 3 consecutive circle data meet the following two conditions:

[0069] No sudden start / emergency stop, S3 judgment does not trigger alarm;

[0070] All under uniform speed working condition , S5 judgment has no fault;

[0071] Then determine that the fault is eliminated or the alarm is misjudged, execute S602;

[0072] If the subsequent data still meet the alarm condition, keep the alarm state and continue monitoring.

[0073] S602: Eliminate mechanical damage alarm system to clear mechanical alarm signal, update the device state to normal monitoring, return to S1, enter the next round of diagnosis cycle.

[0074] Need to be explained additionally:

[0075] Key threshold acquisition method Acquisition: Under the condition of on-site normal flow, collect not less than 100 groups of Circle time consumption data Calculate for each group of data, and take the maximum value of all calculation results as .

[0076] Acquisition: Collect Data of normal flowmeter and abnormal flowmeter containing fixed foreign matter under on-site normal flow, respectively, extract the maximum value of the normal flowmeter (used to confirm that the normal and abnormal data have no intersection interval, and verify the validity of ) and the minimum value of the abnormal flowmeter , take the minimum value of the abnormal flowmeter as .

[0077] Acquisition: Collect the start and stop process data of not less than 10 damaged flowmeters, extract the critical change value of adjacent level time when suddenly accelerating and emergency stopping, respectively determine the upper limit of the last level time When suddenly accelerating, the lower limit of the current level time When suddenly accelerating, the lower limit of the last level time When emergency stopping, the upper limit of the current level time .

[0078] ​The embodiments of the present application are disclosed above, but not limited to, the preferred embodiments, and those skilled in the art can make different deductions and changes according to the above embodiments, and the different deductions and changes should be within the protection scope of the present application as long as they do not deviate from the spirit of the present application.

Claims

1. A method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter, characterized in that, Includes the following steps: S1. Start listening to and capturing the flow meter pulse signal, preprocess to remove invalid data, and extract the effective high / low level duration and single-cycle time; S2. Match the preset normal flow range, determine the normal working conditions and enter S4, and the abnormal working conditions and enter S3. S3. Compare the duration of adjacent levels, determine the sudden acceleration or emergency stop event based on the preset threshold, and trigger an alarm. S4. Analyze the deviation rate of time consumption for multiple consecutive laps. If the standard is met, proceed to S5 at a constant speed. If the standard is not met, return to S1. S5. Calculate the duty cycle deviation value, and distinguish between mechanical wear / foreign object jamming or electromagnetic interference based on the exceedance situation and trigger an alarm. S6. Continuously monitor subsequent signals and clear the alarm status when there are no alarms and the deviation value is normal.

2. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 1, characterized in that, Step S3 specifically includes the following steps: S301: Extract the time of any pair of adjacent high and low levels from the preprocessed signal data and record it as the previous level time. and this level time ; S302: Sudden acceleration judgment: will Compared with the preset acceleration anomaly threshold , Compared with the preset acceleration anomaly threshold Comparison: satisfy > and < If the condition is determined to be sudden acceleration, step S304 is executed; otherwise, step S303 is executed. S303: Emergency Stop Judgment: Will Compared with the preset emergency stop abnormal threshold , Compared with the preset emergency stop abnormal threshold Comparison: satisfy < and > The emergency stop is determined, and step S304 is executed. S304: Triggers the mechanical damage alarm system to generate a mechanical damage warning / alarm signal, outputs alarm information through the display screen and remote communication module, and records the alarm time. , The current traffic volume value facilitates subsequent fault tracing and troubleshooting; If the condition is not met, return to step S1.

3. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 1, characterized in that, In step S4, the formula for determining uniform velocity is: like The system is determined to be operating at a constant speed, and proceeds to S5, where: For continuous The maximum value in the lap time, , For the number of laps, the sample size is... For continuous The minimum value of the lap time. The preset constant speed judgment threshold is used; If the condition is not met, it is determined to be a non-uniform speed operation condition, and the process returns to step S1.

4. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 3, characterized in that, In the uniform velocity determination formula, a preset uniform velocity determination threshold is included. Under normal flow conditions at the site, collect no fewer than 100 sets of data. Loop time data Calculate for each set of data Take the maximum value of all calculation results as .

5. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 1, characterized in that, Step S5 specifically includes the following steps. S501: Calculate the duty cycle deviation coefficient per revolution: if the flow meter is embedded For a magnet, one rotation will produce [ The level sequence of ] For the first High-level time of group For the first The low-level time of the group, for the uniform speed condition determined by S4, is based on the formula. Calculate the duty cycle deviation coefficient for each high and low level group in each cycle. ; S502: Non-uniform mechanical wear / fixed foreign object detection per revolution indivual The values ​​are checked one by one: if any one exists... satisfy To set a preset fault differentiation threshold, if the fault is determined to be non-uniform mechanical wear or the presence of fixed foreign objects, S504 is executed. all All meet Proceed to step S503; S503: Electromagnetic interference detection for each revolution indivual Check each value one by one: If all However, it exists If momentary fluctuations or unstable signal amplitude occur, and mechanical component jamming or wear has been ruled out, it is determined to be electromagnetic interference. Step S505 is then executed. Continuous and stable Return to step S1; S504: Trigger mechanical wear alarm: The system generates a mechanical wear / foreign object jamming alarm signal; S505: Trigger magnetic interference alarm: The system generates an electromagnetic interference alarm signal.

6. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 5, characterized in that, In step S502 Data Acquisition: Data were collected from normal flow meters and abnormal flow meters containing fixed foreign objects at the site under normal flow conditions. Data; Extracting normal flow meters The maximum value is used to confirm the interval where normal and abnormal data do not overlap, and to verify this. The effectiveness of differentiation, extraction of abnormal flow meters Minimum value; take the abnormal flow meter value. Minimum value as .

7. The method for diagnosing mechanical abnormalities and electromagnetic interference in a gas flow meter according to claim 1, characterized in that, Step S6 specifically includes the following steps: S601: Alarm reset condition judgment: If the data of 3 consecutive cycles meets the judgment in step S3, the alarm will not be triggered; if the judgment in step S5, there is no fault, proceed to step S602. S602: Clear the mechanical alarm signal and return to step S1.

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